With the increasing awareness of pollution of the environment, the present invention is directed to the problem of cleaning oil or tar-contaminated materials, such as oil-contaminated soils. The present application is also applicable to the recovery of tars from tar wastes, which may be found, for example, as residues from petroleum refining processes. There is increasing interest in the cleanup of soils contaminated with tarry and/or oily organic matter which can originate from a variety of coal/petroleum-based industries, or from spills that may occur during oil production or transportation, or from pond tailings produced during heavy oil recovery. Extraction of oil-contaminated soils by hot water processes and flotation is not entirely successful due to poor flotation response, poor selectivity and due to the generation of a froth that is difficult to handle. The high viscosity of hydrocarbon contaminants as well as the presence of charred materials with particle sizes over 0.6 mm contributes significantly to the poor release of contaminants from the soil. There is thus need for improving methods for removing oil or tar contamination from soil.
It is thus an object of the present invention to provide a process for separating tarry or oily organic matter from solid inert substantially inorganic feedstocks contaminated with such organic matter.
It is yet another object of the present invention to provide a method for removing oil or tar contamination from soil.
It is yet another object of the present invention to remove the tar from tar refuse and waste.
These and other objects of the present invention will be apparent from the following description and from the practice of the invention.